....What 'fire_up' said. Climb up that ladder all you want, and don't worry about the 200 lb limit.
I too weigh over 240, and have been climbing up on the roof ladder of our various RVs (all of which had that same 200 lb limit) for years and years. Never had one break yet. :)
I agree 100% with fire_up: That 200 lb limit is put there to prevent folks from hanging everything including the kitchen sink from the ladder and going down the road with it. IMO those ladders were never meant to be used for that, although I know many people do.
A 'static' load of a person climbing it when the unit is parked is one thing. A load being bounced around going down the highway at 60 mph is a whole 'nother story. I won't attach ANYTHING to that ladder for stowing when on the road, but have no problem at all using it to climb on the roof when parked.
Ah, this reminds me. I need to get up there and give our roof some attention.